56 University of Michigan 



J. H. and E. B. Williamson, collectors, coll. E. B. W. Type 

 male and allotype female, February 17, 19 17. 



W'e found this species at Cristalina only along the smallest 

 creeks. About lialf the material of both sexes came from the 

 Quebrada Cristalina and the other half from the small tribu- 

 tar}^ of the Quebrada Sabaleticus, mentioned under the dis- 

 cussion of Heteragrion calendnhim. It was not taken along 

 Quebrada La Camelia where we took many specimens 

 of mitratnin. The latter inhabits small streams but gives place 

 to peycgrinmn on the small tributaries and on the headwaters 

 of these streams. Fercgrinmn rests on twig tips or leaf edges. 

 For a Heteragrion it wanders far from water and is found in 

 the brush in shallow short dry gullies between low hills. It 

 is remarkable that the bright yellow prothorax of the male is 

 the conspicuous color area of the insect. This color area is 

 less conspicuous, of course, than the bright yellow "head- 

 lights'* of the males of uiitratitin^ calendnhim, etc. Pcre- 

 grinnni is an alierrant member of group 3 of the genus, but it 

 can not be placed in any other group. This fact and its habit 

 of wandering from the streams make the specific name doubly 

 appropriate. 



A male was' sent to Dr. Ris for examination. He wrote : 

 "I have not seen anything similar to this." 



30. Oxxstignia petiolatnui Selys 



Figures 10, 25, 26, 55, 66, 99, 100, loi, 102, 115, 116, 169, 170 

 :\lale. — Labruni black. Prothorax black, extreme anterior 

 border of front lobe bluish and the lateral margin greenish 

 blue ; middle lobe with a large anterior indefinite greenish-blue 

 spot on either side reaching the lateral margin; hind border 

 of posterior lobe lavender. Propleuron light yellow, bluish 

 in front, darker behind. The narrow lines on either side of 



